Spatial Distribution Of Maize Grain Yield And Main Quality Characteristics And Its Influence Factors In Main Maize-producing Regions Of China

Maize(Zea mays L.),as the source of food,fodder,and processed products for industry,is an important cereal crop.Maize grain yield and compositional quality are highly affected by genotype and environmental factors such as temperature and solar radiation.To evaluate the effects of environmental and genotype on maize grain yield and quality parameters and their relationship across China and give the division of dominant regions with different grain quality,multisite and sowing date experiments were conducted using the hybrids ZD958,XY335,NH101,DH11,ZD909,and local cultivars.The 23experimental sites were located in the North maize region(NM)and Huanghuaihai maize region(HM)of China.The results showed that maize grain yield and the 1000-kernel weight(g)of ZD958,XY335,NH101,DH11,ZD909 were significantly affected by the latitude.The maximum average grain yield(12.25 Mg ha^–1)of the 5 cultivars was observed at the latitude of 43°58?N.Whereas the maximum 1000-kernel weight of the 5 cultivars was weighted(362.08 g)at the latitude of 41°48?N.Five cultivars showed different trends.Among all the climatic factors,minimum temperature and accumulated solar radiation had the best relationships with variations in maize grain yield and 1000-kernel weight.In addition,cultivar XY335 had a higher yield potential at high latitude.The results highlighted that both environment and genotype affected maize grain quality parameters under different regions in both years.Cultivar XY335 had average grain moisture(9.13%),protein content(9.06%),oil(3.91%),starch(74.05%),fiber(3.54%),and bulk density(782 g/l)in 2018 in NM.Grain moisture(9.68%),the content of protein(10.04%),oil(4.44%),starch(72.72%),fiber(3.68),and bulk density(736 g/l)were observed in 2019 in NM.However,it had an average moisture content(9.32%),protein(10.45%),oil(3.45%),starch(72.83%),fiber(3.63%),and bulk density(794 g/l)in2018 and 9.75%,11.45%,4.15%,72.45%,3.85%,and 782.4g/l in 2019 in HM.ZD958 had 9.39%moisture content,8.56%protein content,4.20%oil content,74.19%starch content,3.40%fiber content,and 767 g/l bulk density in 2018 in NM.Moisture(9.98%),protein(9.21%),oil(4.63%),starch(73.38%),fiber(3.53),and bulk density(728.08)were observed in 2019 in NM.Our findings further indicated that cultivars ZD958 had the moisture content(9.55%),protein content(9.60%),oil(4.26%),starch(72.51%),fiber(3.58 g/100)and bulk density(797 g/l)in 2018 and 9.95%,10.45%,4.92%,72.77%,3.88%and 789 g/l in 2019 in HM.Maximum bulk density was observed in 2018 and maximum protein content,oil,and fiber were found in 2019 in the HM.Maximum starch content and moisture content were found in NM in 2019.Among the cultivars,XY335 had maximum protein content while ZD958 had maximum oil content,starch,fiber,bulk density,and moisture content.These two-year research results further suggested that among the main maize production regions,HM was the dominant region for maximum protein and NM is the dominant region for maize starch content.Planting density had no effect on maize grain quality of cultivars ZD958 and XY335 in both regions.Current results suggested that grain yield varied among different regions and cultivars.The average grain yield of ZD958 were 13.08 and 12.31 Mg ha^-1in 2018 and 2019 in NM respectively.In addition,the grain yields were 7.86 and 9.42 Mg ha^-1in 2018 and 2019 in HM.The grain yields of XY335 were12.90 Mg ha^-1in 2018 and 11.12 Mg ha^-1in 2019 in NM.However,the grain yields were 6.93 Mg ha^-1and 9.28 Mg ha^-1in 2018 and 2019 in HM.It was found that maximum maize grain yield was observed in NM for both cultivars in 2018.Further analysis showed that grain starch had a significant relationship with yield for both cultivars.While fat,fiber,and moisture content had no significant relationship with yield.A significant relationship existed between protein,bulk density,and yield for XY335.The sowing date had a significant effect on 1000-kernel weight and yield,and the variation in1000-kernel weight was one of the leading causes for the yield.A reduction in 1000-kernel weight and yield occurred under early or late sowing and the maximum 1000-kernel weight was obtained at S6(June 10)for both cultivars(XY335 and ZD958).The maximum grain yield for XY335 was 16.76 Mg ha^-1at S4(22th May).Cultivar ZD958 had a maximum yield of 16.34 Mg ha^-1at S6(10th June)sowing date.Results showed that XY335 had maximum yield potential.The current research results suggested that the 1000-kernel weight and grain yield were significantly affected by different genotypes.The results revealed that XY335 had the highest grain yield,while cultivar Mingtian 695 had the highest1000-kernel weight among all cultivars in the same environment.